Went to look at a trailer--Help

So I just went to look at a King Cobra 28ft enclosed 2007 trailer and I need help,The asking price is $7500 and it is in pretty good shape,Some scratches on sides (I really don't care) couple little dings (no big deal) it is a all steel trailer and it is wired for 110 with outlet's and ceiling lights,It comes with a built in winch and a few front cabinets (homemade) and the walls and ceilings are the milk house white coverings. Needs all four tires replaced A.S.A.P- but the one thing to me is weird that I really have no knowledge of and here is where I need help--Don't 28ft trailer usually come with three axles????? Also the load limit for the cargo is only 4600 lbs-Doesn't that seem low????? Has dual 5200lb axles on with four wheel brakes--Looking for some knowledge--Thanks Steve